Copyright © 2009 Future Technology Devices International Limited

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Document Reference No.: FT_000119

USB TO RS422 UART SERIAL CONVERTER PCB

Datasheet

Version 1.02

Clearance No.: FTDI#79

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Description

The USB-RS422-PCB is a USB to RS422 level serial UART converter PCB incorporating FTDI’s FT232RQ

USB to Serial UART interface IC device which handles all the USB signalling and protocols. The PCB

provides a fast, simple way to connect devices with a RS422 interface to USB.

Each USB-RS422-PCB contains a small internal electronic circuit board, utilising the FT232R plus a USB

type-A connector. The FT232R datasheet, DS_FT232R, is available at http://www.ftdichip.com. The

integrated electronics also include an RS422 transceiver plus Tx and Rx LEDs which give a visual

indication of UART traffic.

The PCB is USB powered and USB 2.0 full speed compatible. Each PCB supports a data transfer rate up to

3 Mbaud and supports the FTDIChip-ID™, with a unique USB serial number programmed into the

FT232R. This feature can be used to create a security or password protected file transfer access using the

PCB. Further information and examples on this feature are available at http://www.ftdichip.com under

FTDIChip-ID Projects.

The USB-RS422-PCB requires USB drivers, available free from http://www.ftdichip.com, which are

used to make the FT232R on the PCB appear as a virtual COM port (VCP). This then allows the user to

communicate with the USB interface via a standard PC serial emulation port (for example TTY). Another

FTDI USB driver, the D2XX driver, can also be used with application software to directly access the

FT232R on the PCB though a DLL. This is illustrated in the Figure 1.1.

Figure 1.1 Using the USB-RS422-PCB

1.1 Part Number

The following Table 1.1 gives details of the available USB-RS422-PCB.

Part Number

Description

USB-RS422-PCB

USB to RS422 level UART PCB

Table 1.1 USB-RS422-PCB Part Number